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<title>InvMixColumns</title>
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<p>To reverse MixColumns transformation, InvMixColumns <font face="Verdana" size="2">
takes column by column from AES State and performs 
matrix multiplication within Galois field, but with different matrix, as 
follows:</font></p>
<p>
<font face="Courier New" size="2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; | 0e 0b 0d 09 |<br>
new = | 09 0e 0b 0d | * old_column<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; | 0d 09 0e 0b |<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; | 0b 0d 09 0e |<br>
or<br><br>
|n1|&nbsp;&nbsp; | 0e 0b 0d 09 |&nbsp;&nbsp; |o1|<br>
|n2| = | 09 0e 0b 0d | * |o2|<br>
|n3|&nbsp;&nbsp; | 0d 09 0e 0b |&nbsp;&nbsp; |o3|<br>
|n4|&nbsp;&nbsp; | 0b 0d 09 0e |&nbsp;&nbsp; |o4|<br>
&nbsp;</font></p>
<p><font face="Courier New" size="2">To see it in action, just press InvMixColumns 
button. Initial values are from FIPS-197, page 37. Moreover, You can play with 
State values to check results.</font></p>

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